I'd like to start thread on this topic because there isn't one. There is one on compressed air storage but this thread is for other storage technologies too, in particular, the development and recent advances in energy storage. I'll start with an assessment by IEA in 2009, and a second by EU Parliament in 2008.

Prospects for large-scale energy storage in decarbonised power grids

The extent to which a power system can accommodate variations in supply is governed to a large extent by its flexibility – a measure of how fast and how much the system can quickly increase or decrease supply or demand, to maintain balance at all times. A range of measures exist to increase the flexibility of power systems, and thus the extent to which they can accommodate variable renewables. This paper looks at one of these measures – storage.

As mentioned above, as each storage system has different specifications, the optimal arrangement of these systems depends on circumstances in individual countries. In Annex 1, the current technical potential of NaS cells, pumped hydro, redox flow cells, Compressed Air Energy Storage (CAES), electric double-layer capacitors, Li-ion batteries, Superconducting Magnetic Energy Storage (SMES) and flywheel systems is reviewed. Reducing costs of such storage technologies may be a key to expanding the use of energy storage technologies to keep pace with the growth of variable renewables.

This report provides an overview of the current status and outlook for energy storage technologies.Section 1 introduces energy storage and sets out the scope of this study. It also discusses some of the potential applications of the different technologies and reviews briefly some of the economic and environmental issues arising from their deployment. Section 2 sets out an inventory of energy storage technologies, showing how these technologies fall into a number of different technical types. This section also provides a summary of the characteristics of the technologies and their advantages and drawbacks. Section 3 provides a brief summary of the main international research programmes and activities that are in place to support the development of these technologies. Section 4 reviews the most promising technologies for the main potential applications Section 5 considers the policy challenges relevant to the deployment of energy storage technologies, to help in the development of appropriate recommendations. Section 6 sets out a number of appropriate recommendations.

The Technology Showcase at the Advanced Research Projects Agency–Energy Innovation Summit in Washington, D.C., is dotted with projects from companies, national labs, and universities that aim to change how we produce and use energy. They're all ARPA-E awardees, meaning they fall under a number of broader project categories, but what's clear from wandering the floor is how many of them are related to energy storage. A few examples of innovative energy storage projects that ARPA-E is helping get off the ground:

Beacon Power: Scaling up the flywheelFlywheels are an old idea, so why has ARPA-E given Beacon Power more than $4 million? Because this is no ordinary flywheel. "The improved design [pictured] resembles a flying ring that relies on new magnetic bearings to levitate, freeing it to rotate faster and deliver 400 percent as much energy as today's flywheels." Well then.

ARPA-E categorizes the tech as still in the "proof of concept" stage, but Beacon does have at least one large installation of flywheel storage up and running in Stephentown, N.Y. It has built a 20-megawatt plant on 3.5 acres that lets the New York ISO improve its grid frequency regulation.

Sun Catalytix: The artificial leaf growers go for megawatt-scale storageThis company has gotten plenty of press in the last few years, including from us. But that was for work on the so-called "artificial leaf," a small solar device that mimics photosynthesis. Sun Catalytix has spun off some of that research into work on new chemistries for flow batteries, which they say will be able to scale up to grid-level storage. So far they've built kilowatt-scale devices, and are aiming for megawatts.

Energy Storage Systems: An all-iron flow batteryMore flow batteries: Energy Storage Systems leaves behind traditional flow battery materials like vanadium in favor of earth-abundant iron. That is not a trivial change: it drops the per kilowatt-hour cost from around $400 to less than $200. Craig Evans, the company's president and CEO, told me they have a 1 kilowatt prototype now, and will scale up as part of the requirements of their ARPA-E award by the end of the year. And interestingly, ESS isn't the only ARPA-E awardee working on all-iron flow battery tech; Case Western Reserve University is also working toward a $200/kwh battery.

Halotechnics: Molten glass (yes, glass) energy storageSolar thermal systems often now use molten salts to store energy: heat up the salts during the day, and when the sun goes down use that stored energy to keep the power flowing. Halotechnics' ARPA-E-funded project involves abundant glass, instead of salts, that can stay stable hundreds of degrees past other materials and are potentially much cheaper.

There are, impressively, dozens of other storage projects as well. If this trend keeps up, the common talking point regarding the lack of storage options for renewable energy won't have much stable ground under it.

.It's a very good idea ,energy storage is a critical side to energy use

I'll have to go through the links , as a starter and a bit tongue in cheek , the oldest energy storage I can think off,used for millenias up to today is the wood pile the most useful to the grid is reverse pumping of water

P.S. Iron /caustic batteries were in widespread use for their robustness and cheapness they can stand a lot of discharge and last a long time without much maintenance

in fact they are still used today for backup emergency signaling for railwaysthey can stand a fair amount of cold weather , lead acid can't

March 1, 2013 — Largely out of sight, tucked into building basements and stashed in garages, a new generation of energy storage technology is poised to help our aging grid not only avoid outages, but enable vast new flows of renewable power, all while saving some serious money. Call it the smart storage revolution.

California is ground zero for this trend. Across the Golden State, costs for electric power are high, renewables are multiplying, and key grid links are overloaded. But rather than rely on longstanding industry practice to fix grid problems by building more power plants or transmission lines, California regulators are encouraging customers and utilities to innovate.

A menagerie of exotic new storage technologies — including thermal storage, flywheels and compressed air storage — are developing fast, but haven’t yet achieved commercial-scale viability. For now, advanced battery-based storage is the hottest of the grid’s newcomers, thanks to rapid declines in the price of Li-ion batteries.

For those of you who have not seen the following before, this article belongs in this thread (please view video):

Producing Terawatts of Economical Storage in the next two decades

Problem: Wind and solar energy sources simply can't produce power at all times. Energy storage is needed to store energy from the sun and wind when it's produced for use later. No economical, widespread energy storage method currently exists that would allow a substantial portion of the electrical grid's electricty to be supplied by these renewable sources.

Solution: An inexpensive, compressed air energy storage system with 60-70% efficiency could be widely scaled, hopefully enabling terawatts of grid energy storage in the next two decades.

"Our specialty is with large technology risk, where if the technology works there's a big economic breakthrough," said Vinod Khosla, the billionaire founder of Khosla Ventures in Menlo Park. "That's what we keep looking for in all areas."

LightSail Energy, a grid-scale energy storage startup, just added $5.5 million to its coffers. New investor Total, the French Energy giant, joined Peter Thiel, Bill Gates, Khosla Ventures, and Innovacorp in the second closing of its $37.3 million Round D.

François Badoual, CEO of Total Energy Ventures, said in a release, “Energy storage is an important enabler for the long-term development of alternative energies and to ensure the stability of electricity supply." Total is also a major investor in SunPower (NASDAQ:SPWR).

It's still early days for energy storage and for LightSail, of which CEO Steve Crane says, "We've mostly had our heads down trying to productize our technology."

LightSail's funding announcement arrives after last week's energy storage ruling from the California Public Utility Commission (CPUC). The CPUC is asking Southern California Edison to procure 50 megawatts of energy storage over the next eight years, according to a final decision issued Wednesday. It's among the first state regulatory rulings that put grid storage at center stage.

The grid storage market will reach $6.1 billion by 2018 making energy storage one of the fastest growing opportunities in the smart grid industry. Supercapacitors will become integral to grid storage, as costs go down and capacities increase.

By 2018, supercaps will generate $1.1 billion in revenues from grid-storage, especially regenerative braking on grid-attached light rail and frequency regulation. Here supercaps can result in a 30% reduction in electrical costs. The long lifetimes and near-zero maintenance for supercapacitors make them attractive for such applications. Supercaps will improve performance with new materials; including nano-structured metal oxides, perovoskites, nanotubes and graphene increasing capacity 5-10 times compared to activated-carbon supercapacitors.

The default option for grid batteries today is lead-acid, accounting for more than 55% of revenues from grid batteries currently. By 2018, this share will decline to around 30% as new grid battery technologies become commercialized. The lead-acid battery will itself get an upgrade; carbon electrodes, promising a 4x performance improvement. In addition, the ultrabattery, with combination lead/carbon electrodes will compete for grid-storage markets. In 2018, lead-carbon batteries/ultrabatteries will generate around $300 million in revenues.

Grid storage for remote locations, microgrids and cell phone towers are already economically viable. This is driving demand for lead-acid and Zebra (sodium-nickel-chloride) batteries. Another wave of storage deployment is about to occur on the customer side of the meter for power-quality, peak-shaving and grid-stability applications creating demand for flow and lithium-ion batteries. During this second wave the penetration of renewables will rise above 20%, making grid storage necessary to stabilize the grid because of intermittent generation. A final wave of grid storage is expected for retail peak shifting applications.

Although lithium-ion batteries are receiving considerable attention, it is immature and high cost and its current growth relies on government subsidies. When subsidies disappear, sodium-sulfur and Zebra batteries will be a better deal for power companies and large end users than lithium-ion. The best hope for lithium batteries is where a supplier who is committed to lithium sells it as part of a comprehensive solution such as for smart buildings. Jonson Controls and SAFT are doing this. Revenues from lithium batteries are expected to reach $775 million by 2018.

The commercial buildings market is currently the largest source of revenue for stationary energy storage companies, primarily thanks to a robust uninterruptible power supply (UPS) industry, which requires an energy storage component. That segment alone is estimated to generate $3.7 billion in global sales in 2013. In addition, there is a relatively healthy market for thermal energy systems, which use thermal mass (either ice or ceramic bricks) to store energy for later use in climate control in a building. That market is estimated by Pike Research to be worth $89.6 million in 2013. Finally, an emerging segment of electrical energy storage systems is beginning to be established in some parts of the world.

The future growth of energy storage systems for commercial buildings is heavily dependent on the local regulatory environment, both from the perspective of the electric utility's rate structure and government incentives for energy storage systems. In regions where energy storage is incentivized through utility rebates, time-of-use rates with high differentials, or government mandates, growth is expected to be much higher. Pike Research forecasts the market for commercial building energy systems to grow from $3.9 billion in revenue in 2013 to more than $7.5 billion in 2022.

TechNavio's analysts forecast the Global Molten Salt Thermal Energy Storage market to grow at a CAGR of 17.25 percent over the period 2012-2016. One of the key factors contributing to this market growth is the increase in positive attributes of molten salt. The Global Molten Salt Thermal Energy Storage market has also been witnessing the increase in RandD initiatives. However, the decline in solar subsidy rates could pose a challenge to the growth of this market.TechNavio's report, the Global Molten Salt Thermal Energy Storage Market 2012-2016, has been prepared based on an in-depth market analysis with inputs from industry experts. The report covers the Americas, and the APAC and EMEA regions; it also covers the Global Molten Salt Thermal Energy Storage market landscape and its growth prospects in the coming years.

In visiting Australia regularly for the last two decades I have never quite understood why greater value is not placed on the nation’s latent solar and nuclear energy assets. Perhaps it is because Australia thinks there is a vital missing link: the ability to store energy.

With renewable sources such as wind, wave and solar, energy is often created in the wrong place at the wrong time, making it difficult to utilise. Australians aspire to use renewable resources but are thwarted by the practicalities of renewables’ use in future energy generation and supply systems.

In Australia, climate change legislation is driving decarbonisation. This will shift the energy provision and create new markets. The public mind however is on cost, accessibility and security of supply.

In the UK, the electricity generation mix and the opportunities are very different. In November the UK Chancellor announced that energy storage technology was critical to the future UK economy and will be worth £10B a year by 2050.

This value comes from understanding where the different energy storage technologies fit into the grid at generation, transmission and distribution. It’s not simply a matter of providing storage capacity. Governments have to determine how to configure a robust energy system to suit the changing energy mix and minimise the cost of transmission investment as the demand for electrical power grows.

Which way is the best way?

Liquid air a great alternative

As Figure 3 shows, there are alternatives to batteries. For example, in the UK there is a growing interest in the notion of cryogenic liquids. These are reported to be a cheaper and better way to use solar energy to drive compressors to compress air to liquid air (as cryogenic fluids).

Liquid air is potentially an energy vector in itself; vapourising the liquid using low grade waste heat makes for a very efficient system that then drives a generator.

The round-trip efficiency of these systems rivals batteries. These have now been demonstrated at a small scale with 350kW/2.5MWh scale for on-grid electrical storage and further developments to scale out to beyond 10MW are underway. Some 100MW+ systems with GWhs of storage are deliverable using existing supply chains and components. Some comparisons of estimated costs for comparative storage systems have been mooted (see Table 1).

Australia’s hydro energy storage systems are getting long in the tooth: maybe it’s time to look at liquid air. Michael MazengarbIn visiting Australia regularly for the last two decades I have never quite understood why greater value is not placed on the nation’s latent solar and nuclear energy assets. Perhaps it is because Australia thinks there is a vital missing link: the ability to store energy.

With renewable sources such as wind, wave and solar, energy is often created in the wrong place at the wrong time, making it difficult to utilise. Australians aspire to use renewable resources but are thwarted by the practicalities of renewables’ use in future energy generation and supply systems.

In Australia, climate change legislation is driving decarbonisation. This will shift the energy provision and create new markets. The public mind however is on cost, accessibility and security of supply.

In the UK, the electricity generation mix and the opportunities are very different. In November the UK Chancellor announced that energy storage technology was critical to the future UK economy and will be worth £10B a year by 2050.

This value comes from understanding where the different energy storage technologies fit into the grid at generation, transmission and distribution. It’s not simply a matter of providing storage capacity. Governments have to determine how to configure a robust energy system to suit the changing energy mix and minimise the cost of transmission investment as the demand for electrical power grows.

Which way is the best way?

Different applications demand appropriate storage characteristics and a range of technologies are needed to suit the specific needs. Technologically speaking, energy can be stored in mechanical, electrical or chemical devices and in the form of heat. All are probably needed, but – apart from hydro-storage dams – Australia has few examples at a significant scale.

So what might energy storage mean for Australia?

It certainly should not mean simply filling the country with batteries for storing renewable energy.

There have been some extensive battery park trials for regional storage in China and in the US (Figures 1 and 2) and in other energy constrained countries (such as Chile), but this does not appear to be a widespread option suited for Australia.

Figure 1: Chinese energy storage.

Figure 2: US energy storage.Conventional batteries of different types have their place, but society really needs an alternative. This is not only driven by realisation of the cost, resource wastefulness, environmental impact and scarcity associated with rare earths components, but also by a growing public misgiving about safety.

Battery-related safety incidents have been growing rapidly over the last few years, in vehicular and air transportation, computers, large scale battery parks and wind/solar on site storage locations.

A range of energy storage methods are currently available; most of these have been reviewed recently. Figure 3 shows a summary based upon the scale of power rating and the call down time, expressed here as a discharge time at rated power.

Figure 3: System power ratingsClick to enlargeLiquid air a great alternative

As Figure 3 shows, there are alternatives to batteries. For example, in the UK there is a growing interest in the notion of cryogenic liquids. These are reported to be a cheaper and better way to use solar energy to drive compressors to compress air to liquid air (as cryogenic fluids).

Liquid air is potentially an energy vector in itself; vapourising the liquid using low grade waste heat makes for a very efficient system that then drives a generator.

The round-trip efficiency of these systems rivals batteries. These have now been demonstrated at a small scale with 350kW/2.5MWh scale for on-grid electrical storage and further developments to scale out to beyond 10MW are underway. Some 100MW+ systems with GWhs of storage are deliverable using existing supply chains and components. Some comparisons of estimated costs for comparative storage systems have been mooted (see Table 1).

Table 1: Costs of storage systems.Click to enlargeSuch systems offer a means for low cost off-grid generation. This can smooth power requirements and provide security of supply by creating a national reserve.

Liquid air can also be used directly as a fuel. The first “cars that run on air” are currently being evaluated and are attracting significant attention. Australia, like the UK, has existing infrastructure to support early adoption. The technology is from a mature supply chain and components with proven long life whose costs are known.

Liquid air storage is at low or atmospheric pressure, resulting in low cost, above ground, safe bulk tanks. There is no fuel combustion risk. There are no geological or geographical constraints to location of stores or distribution pathways.

The energy density of liquid air compares favourably to other low-carbon competitors. There is great synergy with other industrial processes, including use of waste heat and provision of cold. And liquid air can be used as an energy vector to transport this stored energy around by road (as is currently done) or ship (as with LNG).

A major review of this opportunity is underway and may have profound application for Australia if it turns out that liquid air can be used as a fuel. Meanwhile the UK Energy and Climate Change Minister John Hayes believes that liquid air may offer some radical solution with real economic stimulus to the economy.

NETZSCH Instrument North America, LLC and the US Department of Energy’s (DOE) National Renewable Energy Laboratory (NREL) are collaborating to develop a new isothermal calorimeter to test the performance and safety of Large Format Li-Ion Batteries (LFLIBs) used extensively in electric vehicles, airplanes, military application, as well as stationary power back-up and storage applications.

The new isothermal calorimeter will be based on patent-pending technology developed by a team of NREL researchers. The instrumentation will be able safely and accurately to characterize heat output and efficiency of LFLIBs, in varying temperature, pressure, load and use conditions, providing precise and critical information previously unavailable.

A strategic alliance between French company McPhy and the Spanish Ecowill Engineering Group is to develop a renewable hydrogen solution for the Colombian market. The first ‘green hydrogen’ plant will be installed near Bogotá.

Hydrogen produced using wind or solar power will be stored in solid form in containers using McPhy technology. The hydrogen is produced by electrolysis of water, using renewable energy sources, before being absorbed by discs of magnesium. The two elements combine to form magnesium hydride, storing the hydrogen in a stable and relatively dense form. The process allows large amounts of hydrogen to be stored at low pressure (10 bar), thereby facilitating its transport.

"To meet the needs of the Colombian market, we will have six containers of two and a half meters wide, which will store up to two megawatts each. Where it is possible to install an external heat exchanger, we can store nearly 23 megawatts in the same volume”, says Guillaume d'Arche who represents McPhy in Spain, Portugal and South America.

Easy to fill and empty, these containers can be transported safely and used for many applications. The energy contained in them can be used to produce electricity through a combustion engine, a fuel cell or a gas turbine. Hydrogen can also be used as vehicle fuel.

With researchers over the globe battling to bring down the cost of wind and solar electricity with innovative wind turbines and highly efficient solar panels, the last piece of the equation, which is energy storage, plays a critical role in reducing the overall cost of clean electricity. Since the sun doesn’t shine all day nor does the wind blow continuously, storing all the energy generated when available for use when needed, requires energy storage systems, which currently cost a lot. As a solution to the problem of finding cheap energy storage systems, engineer Bill Gray has come up with the Velkess.

The Velkess is a low-cost flywheel energy storage system that can easily replace conventional lead-acid batteries used in solar power plants around the world. While flywheels have been in use for over 100 year and have proved to be among the highest performing energy storage technologies ever developed, they have suffered one fatal flow – high cost. Velkess on the other hand is a highly affordable energy storage flywheel that costs half of conventional energy storage systems and performs three-five times better.

The topic presumes that the energy is stored after it has been released from another physical state. Clearly this represents a massive problem and seems disingenuous. The presently known solutions are basically limited to batteries, capacitors, water towers, pressure vessels, heat sinks or mechanical devices all of which are inefficient, have very limited unit capacity and would serve only very local and small scale needs.Clearly, we already have massive energy storage in the form of hydraulic dams and in the miriads of fuel dumps around the world. It can't get better than that. But it can get a lot worse.Having released the energy inherent in a fuel, why on earth would you want to try to stuff it back in the bag again, so to speak, and on a large scale at that?

lper100km wrote:Having released the energy inherent in a fuel, why on earth would you want to try to stuff it back in the bag again, so to speak, and on a large scale at that?

Normally you wouldn't. You want to stuff the energy in a bag not when it comes from a fuel(Which are fantastic bags BTW), but when it comes from the fickle ebb and flow of solar and wind sources. You see these sources tend not to cooperate and often produce power when we don't need it(Wind often blows hardest at night, when grid demand is lowest). However if you could stuff all of that energy produced by wind at night when demand is lowest and then release it during the day when demand peaks, you could save yourself from having to build new expensive peaker power plants.

Variable renewables are not the only power source that could benefit from energy storage. Baseload power such as nuclear is another one. You see, nuclear has astronomical capital costs, but low maintenance costs. It is also not an easy matter to shutdown and restart reactors. All of these factors combined means nuclear is best suited for baseload generation. In other words, you only want as much nuclear power in your grid to cover the lowest level of demand the grid will ever have. It just isn't well suited to handle variable peaker loads. Energy storage could change that. If you could store up the excess amount of power nuclear plants generate over baseload during low grid demand, then you can release it later during high grid demand.

Nuclear plants have high capital costs and low operating costs that favor base-load operation. This characteristic of nuclear power has been a critical constraint that limits the portion of nuclear power plants in a grid to stay below the base-load demand. A novel gigawatt-year thermal-energy storage technology is proposed to enable base load nuclear plants to produce variable electricity to meet seasonal variations in electricity demand. A large volume of underground rock is heated with hot water (or steam or carbon dioxide) from a nuclear power plant during periods of low electricity demand, and the heat is extracted during times of high demand and converted to electricity using a standard geothermal plant. Peak power electricity is produced by exploiting the stored thermal energy via an Enhanced Geothermal System (EGS).

The nuclear-EGS storage system introduces economic benefits to a grid by leveraging economic gains arising from replacing expensive intermediate and peak electricity with cheap base-load electricity. A nuclear-EGS system has a higher capital cost than natural gas turbines; consequently, it replaces intermediate-load power plants but not all the gas turbines that operate for a small number of hours per year. It was found that the deployment of a operate for a small number of hours per year. It was found that the deployment of a Nuclear-EGS could cut the electricity production cost of the New England Independent Systems Operator (NE-ISO) by as much as 14% of the storage-free cost. Like any other system dependent upon geology, costs and performance will depend upon the local geology.

Well, you are talking some hugely large scale storage here. If you want to smooth peaks etc on grid systems, that's a massive problem for the kind of solutions that are being discussed so far. They won't even scratch the surface. Some of these geo heat sink proposals seem just way out. Why not drill a really deep hole, pump water into it and get steam out. It's just as plausible as anything else.

I have to agree that energy storage alone is not the answer. But it can play a role as part of a larger smart grid initiative. In fact, the biggest chunk of smart grid investments hasn't even been energy storage. It has been smart meters and associated services(demand response, home energy management, smart electric vehicle charging, etc.)

Global smart grid investment grew 7% in 2012 to US$13.9 billion, according to figures from Bloomberg New Energy Finance. In terms of geographic spread, the sector mirrors photovoltaics with the U.S. clinging to top spot but due to be replaced by China in 2013, in large part thanks to a willingness to invest in smart grid technology by the Chinese government.

The largest share of the global investment, around $7.1bn, was devoted to smart metering and associated services and infrastructure costs with distribution automation and integrated demonstration projects of features like demand response, home energy management and smart electric vehicle charging, the next most popular investments.

Bloomberg is predicting a compound annual growth rate of investment of 10.4% globally over the next five years, taking worldwide smart grid investment to $25.2bn by 2018.

Global investment in smart grid technologies totaled $13.9 billion worldwide in 2012. Smart girds, which are electricity networks that use digital information and communications technologies for more efficient and reliable electricity transport, are needed to facilitate the integration of more renewable energy into the grid. With more and more countries shifting towards increasing the shares of renewable energy into their energy mix and upgrading aging grid infrastructure to be more energy efficient, the market for smart grid technologies has been rising as well.

The United States maintained its position as a leader in smart grid investment, spending $4.3 billion in 2012. China followed close with $3.2 billion in investments in 2012. China has been stepping up its smart grid investments ushered by the government’s plans to update its poorly designed and inefficient transmission system. The State Grid Corporation of China has a three-phase plan to invest $601 billion in transmission infrastructure, with $101 billion for smart grid technology through 2020. If China continues to invest heavily in smart grid technology, they could surpass the U.S. as world leader by 2013.

Aside from smart meters, grid-scale energy storage technologies are another vital aspect of smart grids, especially with regards to the drive to add more renewable energy to the grid. According to Worldwatch, the next few years will see numerous smart grid deployment projects and advances in energy storage markets.

IntroductionEnergy storage is a critical component of the future Smart Grid. According to NanoMarkets, there is a sizeable opportunity for new materials and systems for supercapacitors and chemical batteries, which are critical components in Smart Grid electrical storage applications. Supercapacitors and chemical batteries find greater market potential in most applications as they are not confined by certain geological locations and free from the potential environmental impact problems of pumped hydro.

Current Grid Storage LandscapeSmart Grid is a still-evolving term, covering all developments currently being made and planned to the existing electrical grid to improve efficiency, security, reliability, while reducing costs. The following two applications will dominate growth in the near term:

The first application is power quality in sophisticated markets. The growth of state-of-the-art production facilities and the ubiquitous application of electronics make short-term storage as a standard feature that facilitates advanced electronics equipment to face short-term (from a few seconds to a few cycles) power quality issues.The second application is to deliver power leveling in regions with considerable percentages of intermittent generating sources such as solar and wind on the grid. The intermittent nature of these power generating sources needs stored energy, which can be supplied to the grid at a moment’s notice.Considerable energy storage is mandatory to meet the 2030 renewable energy state and federal mandates.

Near-Term Applications for Chemical Storage on the Smart GridEnergy storagePower quality in the context of uninterrupted power supplies has been the most common utilization of large-scale chemical energy storage. Metal hydride and lead-acid batteries are the key system of this industry. However, supercapacitors and integrated supercapacitor/battery backup systems can also make sizeable inroads in this application as they exhibit significantly quicker response times when compared to batteries alone. The reduced cost of supercapacitors makes more common applications of the technology more economical, especially in combination with batteries.

This will expand the market for supercapacitors beyond certain mission critical applications and data centers to include the safety of electronic assets for production facilities, office buildings, retailers, as well as new home construction applications.

A team of researchers at MIT has described a framework for efficiently coupling the power output of a series-connected string of single-band-gap solar cells to an electrochemical process that produces storable fuels. The open access paper, published in the Proceedings of the National Academy of Sciences (PNAS), offers a roadmap for direct solar-to-fuels devices.

The new analysis follows up on 2011 research that produced a proof of concept of an artificial leaf—a small device that, when placed in a container of water and exposed to sunlight, would produce bubbles of hydrogen and oxygen. (Earlier post.) The new work outlines a research program to improve the efficiency of these systems, and could quickly lead to the production of a practical, inexpensive and commercially viable prototype.

The original demonstration leaf in 2011 had low efficiencies, converting less than 4.7% of sunlight into fuel. The team’s new analysis shows that efficiencies of 16% or more should now be possible using single-bandgap semiconductors, such as crystalline silicon, or 18% for gallium arsenide cells.

Such a system would use sunlight to produce a storable fuel, such as hydrogen, instead of electricity for immediate use. This fuel could then be used on demand to generate electricity through a fuel cell or other device. This process would liberate solar energy for use when the sun isn’t shining, and open up a host of potential new applications.

I hink what Germany is doing with free power days when the wind really blows could help solve this. People could buy electric cars and charge them when the gas is free. Refrigerators with large thermal mass. This could be solved small scale. It seems like one of those " If you build it they will come kind of problems."

Cheyenne company seeks to build facility to store energy generated by wind turbines

A Wyoming company hopes to begin testing what could be a game-changing way to store energy generated by wind turbines at a small project site near Guernsey by late 2014.

The energy storage problem sparks a common criticism of wind energy. Critics often target wind power's failure to generate consistent power levels, because producers can't control when the wind blows and can't store the energy generated by their turbines.

Instead of power being created by generators in the nacelle, or top, of the tower, hydraulic pumps are attached to the turbines in Winhyne's tower. As the turbines rotate, the pumps move, generating pressure, which is used to turn a hydraulic motor and spin a generator.

If power from the turbine isn't immediately needed, that same pressure is used to compress nitrogen into a pipeline system. Byrne said the nitrogen can be stored in the pipelines until power from the system is needed, at which point the company can release the gas at a controlled rate, powering the motor and generator.